阅读说明：本技术 一种高亚油酸玉米自交系的选育方法及其应用 (Breeding method and application of high linoleic acid maize inbred line ) 是由 刘晓飞 王卫军 崔小平 孙宝林 于 2019-12-13 设计创作，主要内容包括：本发明提供了一种高亚油酸玉米自交系的选育方法,涉及玉米新品种选育技术领域。本发明所述选育方法通过基础群体构建、辐射诱变,结合亚油酸含量检测,经过连续自交选育高亚油酸玉米自交系,使得自交系后代脂肪酸中亚油酸含量超过60％。在本发明实施例中,经过S4-S6代连续配合力测定,筛选出来的高亚油酸自交系YM-2综合性状表现优良,脂肪酸中亚油酸含量达到61％,耐高温,抗南方锈病,高抗茎腐病、玉米螟、病毒病,中抗大小斑病,高抗倒伏。因此运用本发明的方法以这些自交系作为亲本,用于组配,能够培育出亚油酸含量更高的玉米杂交种,进一步增加普通玉米的营养成分,提升其作为饲用玉米或者开发为保健食品的价值,提高经济效益。(The invention provides a breeding method of a high linoleic acid maize inbred line, and relates to the technical field of breeding of new maize varieties. The breeding method provided by the invention has the advantages that through basic population construction, radiation mutagenesis, linoleic acid content detection and continuous selfing, the high-linoleic acid maize inbred line is bred, so that the linoleic acid content in the progeny fatty acid of the inbred line is over 60%. In the embodiment of the invention, through continuous combining ability determination of S4-S6 generations, the screened high linoleic acid inbred line YM-2 has excellent comprehensive properties, the linoleic acid content in fatty acid reaches 61%, and the high linoleic acid inbred line YM-2 is resistant to high temperature, southern rust, stem rot, corn borer and virus diseases, large and small leaf spot and lodging. Therefore, the method of the invention uses the inbred lines as parents for combination, can cultivate the corn hybrid with higher linoleic acid content, further increases the nutrient content of the common corn, improves the value of the common corn as the feed corn or the common corn developed as health food, and improves the economic benefit.)

1. A breeding method of a high linoleic acid maize inbred line is characterized by comprising the following steps:

(1) hybridizing Suyu 20 and Yun Rui 21 to obtain a first filial generation, and hybridizing the first filial generation serving as a male parent and a maize inbred line K12 serving as a female parent to obtain a basic population S0;

(2) carrying out irradiation mutagenesis treatment on the basic population S0 to obtain a mutagenized population;

(3) planting the mutagenic colony, selfing, detecting the linoleic acid content of the selfed seeds, screening the seeds with the linoleic acid content of more than 60% in fatty acid, and performing self-crossing for S1 generations;

(4) continuously selfing the selfed S1 generations for five generations to obtain a high linoleic acid maize selfing line; in the continuous selfing process, seeds with linoleic acid content of more than 60% in fatty acid are screened for each generation to carry out next generation selfing.

2. The breeding method according to claim 1, wherein the irradiation mutagenesis treatment in step (2) comprises 60 Co-gamma ray irradiation mutagenesis.

3. The breeding method according to claim 2, wherein the irradiation dose of the 60 Co-gamma ray irradiation mutagenesis is 200Gy, and the dose rate is 1.52 Gy/min.

4. The breeding method according to claim 1, wherein in the step (3), the linoleic acid content is detected by gas chromatography.

5. The breeding method according to claim 4, wherein 2-3g of seeds are taken from each ear for linoleic acid content detection.

6. The breeding method according to claim 1, wherein in the continuous selfing process in step (4), each generation further comprises plant type screening and resistance identification, and strains with excellent comprehensive properties are selected for next generation selfing.

7. The breeding method according to claim 1, wherein in the step (4), during the continuous selfing, during the selfing of generations S4-S6, the method further comprises selfing line combining ability determination, and strains with grain length, grain thickness, grain row number, grain weight, positive combining ability effect of seed yield and plant height, and negative combining ability effect of resistance are screened for next generation selfing.

8. The breeding method according to claim 7, wherein the measuring of the combining ability comprises: zheng 58, Chang 7-2, PH4CV and Su 95-1.

9. Use of the high linoleic acid maize inbred line selected by the breeding method of any one of claims 1 to 8 for the preparation of commercial species of maize.

10. The use of the high linoleic acid maize inbred line bred by the breeding method of any one of claims 1 to 8 in breeding of forage maize and health maize.

Technical Field

The invention belongs to the technical field of new corn variety breeding, and particularly relates to a breeding method of a high linoleic acid corn inbred line.

Background

Corn kernel contains many fatty acids, with the highest linoleic acid content. Linoleic acid is an unsaturated fatty acid that is essential to the human body but is not synthesized in the body by itself and must be taken from food. A plurality of studies show that if the human body lacks linoleic acid, a series of cardiovascular and cerebrovascular diseases, such as hypertension, cerebral hemorrhage, heart disease, cardiac and cerebral blood hyperviscosity, hemiplegia, stroke and the like, can be caused. Linoleic acid can soften heart and cerebral vessels, promote blood circulation, reduce blood fat and blood pressure, promote metabolism, regulate endocrine, delay aging and the like, and has the reputation of 'blood vessel scavenger'.

At present, the content of linoleic acid in corn kernels accounts for 40-55% of the total fatty acids in production, and is even lower. Although the total energy level of corn kernels is greatly improved by high-oil (high-fatty acid) corn, a plurality of nutrient components of the corn kernels are improved, the total fatty acid content of the corn kernels is obviously improved, and the absolute content of the total fatty acid and linoleic acid of the specially-planted high-oil corn is higher than that of the ordinary corn, the proportion of the linoleic acid in the total fatty acid is not obviously improved, and the high-oil corn is not popularized and applied in a large area due to various limiting factors. Therefore, there is a need for increasing the proportion of linoleic acid content in common corn fatty acids.

Disclosure of Invention

In view of the above, the invention aims to provide a method for breeding a high linoleic acid maize inbred line, which overcomes the defect of narrow genetic basis of maize germplasm materials, increases the gene frequency for controlling linoleic acid synthesis, increases the linoleic acid content to more than 60% of the total fatty acid content, improves the current situation that the linoleic acid content of common maize is low, and can greatly enrich the nutritional value of common maize as feed or health-care edible products.

In order to achieve the above object, the present invention provides the following technical solutions:

the invention provides a breeding method of a high linoleic acid maize inbred line, which comprises the following steps: (1) hybridizing Suyu 20 and Yun Rui 21 to obtain a first filial generation, and hybridizing the first filial generation serving as a male parent and a maize inbred line K12 serving as a female parent to obtain a basic population S0;

(2) carrying out irradiation mutagenesis treatment on the basic population S0 to obtain a mutagenized population;

(3) planting the mutagenic colony, selfing, detecting the linoleic acid content of the selfed seeds, screening the seeds with the linoleic acid content of more than 60% in fatty acid, and performing self-crossing for S1 generations;

(4) continuously selfing the selfed S1 generations for five generations to obtain a high linoleic acid maize selfing line; in the continuous selfing process, seeds with linoleic acid content of more than 60% in fatty acid are screened for each generation to carry out next generation selfing.

Preferably, the irradiation mutagenesis treatment in the step (2) comprises 60 Co-gamma ray irradiation mutagenesis.

Preferably, the irradiation dose of the 60 Co-gamma ray irradiation mutagenesis is 200Gy, and the dose rate is 1.52 Gy/min.

Preferably, in the step (3), the linoleic acid content is detected by gas chromatography.

Preferably, 2-3g of seeds are taken from each cluster for linoleic acid content detection.

Preferably, in the continuous selfing process in step (4), each generation further comprises plant type screening and resistance identification, and strains with excellent comprehensive properties are selected for next generation selfing.

Preferably, in the continuous selfing process in step (4), in the selfing process from S4 to S6 generations, selfing line combining ability determination is further included, and strains with a positive combining ability effect of ear length, ear thickness, ear row number, row grain number, hundred grain weight and seed yield and a negative combining ability effect of plant height and resistance are screened for next generation selfing.

Preferably, the measuring system for measuring the binding force comprises: zheng 58, Chang 7-2, PH4CV and Su 95-1.

The invention also provides the application of the high linoleic acid maize inbred line bred by the breeding method in preparing commercial maize strains.

The invention also provides the application of the high linoleic acid maize inbred line bred by the breeding method in breeding of feeding maize and health-care maize.

The invention provides a breeding method of a high linoleic acid maize inbred line, which is characterized in that the linoleic acid content in progeny fatty acid of the inbred line is over 60 percent by constructing a basic population, carrying out radiation mutagenesis, combining with linoleic acid content detection and carrying out continuous inbred breeding on the high linoleic acid maize inbred line. In the embodiment of the invention, through continuous combining ability determination of S4-S6 generations, the screened high linoleic acid inbred line YM-2 has excellent comprehensive properties, the linoleic acid content in fatty acid reaches 61%, and the high linoleic acid inbred line YM-2 is resistant to high temperature, southern rust, stem rot, corn borer and virus diseases, large and small leaf spot and lodging. Therefore, the inbred line selected by the method is used as a parent for combination, the maize hybrid with higher linoleic acid content is cultivated, the utilization value of the maize as the feeding maize and the health food is further developed, and the economic benefit is improved.

Detailed Description

The invention provides a breeding method of a high linoleic acid maize inbred line, which comprises the following steps:

(1) hybridizing Suyu 20 and Yun Rui 21 to obtain a first filial generation, and hybridizing the first filial generation serving as a male parent and a maize inbred line K12 serving as a female parent to obtain a basic population S0;

(2) carrying out irradiation mutagenesis treatment on the basic population S0 to obtain a mutagenized population;

(3) planting the mutagenic colony, selfing, detecting the linoleic acid content of the selfed seeds, screening the seeds with the linoleic acid content of more than 60% in fatty acid, and performing self-crossing for S1 generations;

(4) continuously selfing the selfed S1 generations for five generations to obtain a high linoleic acid maize selfing line; in the continuous selfing process, seeds with linoleic acid content of more than 60% in fatty acid are screened for each generation to carry out next generation selfing.

In the breeding method, the first filial generation is obtained after the Suyu 20 and the Yun Rui 21 are hybridized, and the first filial generation is taken as a male parent and a maize inbred line K12 is taken as a female parent to be hybridized to obtain a basic population S0. The Yun 20 and the Yun 21 are hybridized, preferably the Yun 21 is taken as a male parent, the Yun 20 is taken as a female parent, the first filial generation is named SY12-1 in the embodiment of the invention, and the phenotype is represented by medium short stalk, disease resistance and big ear. The sources of the suyu 20 and the yunry 21 according to the present invention are not particularly limited, and are preferably conventional commercially available seeds in the art. The SY12-1 is taken as a male parent, a maize inbred line K12 is taken as a female parent for hybridization, and the method for hybridization is not particularly limited, and the conventional hybridization method in the field is utilized. The maize inbred line K12 is a second-cycle line bred by the filial generation of the Huang Zao SixVirol, and is a male parent of the current variety Shaandan 902. In the present example, a total of two hybrid ears were obtained and made into the basal population S0.

After obtaining the basic population S0, the invention carries out irradiation mutagenesis treatment on the basic population S0 to obtain a mutagenic population. The irradiation mutagenesis treatment is preferably performed by using 60 Co-gamma ray irradiation mutagenesis, and when the irradiation mutagenesis is performed, the irradiation dose is preferably set to be 200Gy and the dose rate is preferably set to be 1.52 Gy/min.

After obtaining the mutagenic population, the mutagenic population is planted and selfed, the linoleic acid content of the seed obtained by selfing is detected, and the seed with the linoleic acid content of more than 60 percent in fatty acid is screened and obtained from the S1 generation. The seeds after irradiation mutagenesis are all planted, all selfed in the pollination period, and harvested by single spike numbering in the harvesting period. According to the invention, the content of linoleic acid in the harvested seeds is detected, the method for detecting the content of linoleic acid is not particularly limited, the method is preferably performed by using a gas chromatography, more preferably, 2-3g of seeds are taken for each ear of grain to be detected, and the high-linoleic-acid corn seeds with the linoleic acid content of more than 60% in S1-generation fatty acid are selected.

After obtaining inbred S1 generations, continuously inbred the inbred S1 generations for five generations to obtain a high linoleic acid maize inbred line; in the continuous selfing process, strains with linoleic acid content of more than 60% in fatty acid are screened for each generation to carry out next generation selfing. The invention continuously selfs the selfing S1 generation for 3 generations, selects 6-8 selfing single ears for each ear row for the next generation to continue breeding, combines the linoleic acid content determination and the screening of the material with compact plant type, 5-grade and above resistance grade and lodging rate of less than 5 percent, follows the principle of selecting more superior people and selecting less inferior people and even eliminating the inferior people, and obtains the S4 generation material. The materials from generation S4 to S6 were subjected to selfing line combining ability determination in addition to normal selfing and linoleic acid content determination. The measuring system for measuring the combining ability of the invention comprises: zheng 58, Chang 7-2, Su 95-1 and PH4 CV. Zheng 58 and Chang 7-2 are preferably from Zhengdan 958 female parent and male parent, Su 95-1 and PH4CV are from Suyu 18 female parent and Xiyu 335 male parent. In the embodiment of the invention, 2 panicle lines are selected at S6 generation according to the general combining ability effect value of an inbred line, wherein YM-2 is a high linoleic acid maize inbred line with medium short stalk, disease resistance, lodging resistance, long fruit ear and hard grain type, the total fatty acid content is 3.5%, the linoleic acid content in fatty acid reaches 61.3%, the content ratio of the linoleic acid in the fatty acid is increased by 23.3% compared with that of K12, the plant type is semi-compact, the tassel glume pieces are light green, the pollen amount is large, the flower filaments are yellow green, the leaves are straight and straight, medium-width, the leaves are light green, slightly yellow and light green spaced stripes are formed, and the grains are orange yellow and semi-hard.

The invention also provides the application of the high linoleic acid maize inbred line bred by the breeding method in preparing commercial maize strains. In the application of the present invention, it is preferable that a new commercial hybrid is obtained after hybridization using YM-2 as a parent. In the embodiment of the invention, a hybrid combination prepared by taking YM-2 as a female parent is characterized by multiple points in Hainan and Jiangsu, and has the advantages of high temperature resistance, rust resistance, high lodging resistance, 105 days of growth period, semi-compact plant type, low spike position, high temperature resistance in powder scattering period, cylindrical fruit cluster, yellow and semi-hard grains, 4.8 percent of total fatty acid content, 61.5 percent of linoleic acid content in the average proportion of the total fatty acid, and 605.7Kg of yield.

The invention also provides the application of the high linoleic acid maize inbred line bred by the breeding method in breeding of feeding maize and health-care maize.

The breeding method and application of the high linoleic acid maize inbred line provided by the invention are described in detail below with reference to examples, but they should not be construed as limiting the scope of the invention.